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Posted (edited)
2 hours ago, Titan said:

 

No. All at standard tension/stiffness.

So is there a contractual restriction that prevents the necessary changes being made? Or is it just a question of cost v benefit?

Edited by rodent279

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Posted (edited)
2 hours ago, rodent279 said:

So is there a contractual restriction that prevents the necessary changes being made? Or is it just a question of cost v benefit?

 

Neither really.  It is just that as far as I am aware no one else has worked out how to do it, but having read the report written by Gary Keanor who did the computer modelling, about what was actually done there is scope for minor adjustments making things a lot better.  I think Network rail asked Gary/Atkins the wrong question - "How fast can we go with what we have got without making any changes?" -  answer 115mph.  But having seen the wire profile in the report, there is a lot of scope for making it better with minor adjustments requiring possibly only one overnight possession for the changes.

Edited by Titan
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7 hours ago, Joseph_Pestell said:

 

I see that this subject has reared its head again!

 

What is it about this particular village that causes such difficulties? It seems able to enrol more objectors than the whole of the Chilterns can raise against HS2.

 

1) There is space to build a road to link the part of the village that is south of the crossings to the old A34 south of the bridge. That would benefit much of the village as it would remove HGVs going to/from the industrial estate.

2) There is space to build a new road and bridge a bit further east (or a temporary bridge while they rebuild the old one).

3) Footbridges can be put in for pedestrians. 


It is a very busy road linking quite a lot of various villages to several industrial estates for commuters (Milton Park, Harwell, Steventon storage etc. To grove, Wantage, Hanney, standford jn the vale, etc) And the other roads are at capacity. A single broken down car on the A417 between Wantage and Harwell in rush hour can cause two hour delays to all the surrounding roads ( and I do literally mean staff finishing at 17:00 on Milton park arriving back in Wantage at 19:00 or later). A34 closures can be worse....my wife travels from Abingdon to didcot on public transport and has resorted to getting a bus to Radley and the train to didcot on the worst occasions.
 

south of the railway line is a very steep slope and would need substantial landscaping for a link road.

 

(there are also some significant private property ownership disputes in progress in the area, and a compulsory purchase order would need them resolved before it could be actioned...)

 

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1 hour ago, Jonboy said:


It is a very busy road linking quite a lot of various villages to several industrial estates for commuters (Milton Park, Harwell, Steventon storage etc. To grove, Wantage, Hanney, standford jn the vale, etc) And the other roads are at capacity. A single broken down car on the A417 between Wantage and Harwell in rush hour can cause two hour delays to all the surrounding roads ( and I do literally mean staff finishing at 17:00 on Milton park arriving back in Wantage at 19:00 or later). A34 closures can be worse....my wife travels from Abingdon to didcot on public transport and has resorted to getting a bus to Radley and the train to didcot on the worst occasions.
 

south of the railway line is a very steep slope and would need substantial landscaping for a link road.

 

(there are also some significant private property ownership disputes in progress in the area, and a compulsory purchase order would need them resolved before it could be actioned...)

 

I am perfectly familiar with the location. I used to drive around there every weekday.

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14 hours ago, DY444 said:

 

I've heard it suggested that a compromise to avoid closure of the crossing is that a road vehicle height limit could be imposed as a way of reducing the contact wire height there and thus its gradient approaching the bridge.  Obviously there would have to be a robust structure of some sort each side to stop over height vehicles and it does sound like something that would fall foul of the H&S mafia but it is a theoretical option ...

 

Similar to this one?

 

 

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8 hours ago, talisman56 said:

 

Similar to this one?

 

 

 

Yes.  That very bridge is precisely what I had in mind :good_mini:

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I assume you are referring to the sacrificial beam rather than the signal system, which seems to be ignored regularly at that bridge. BTW there is a lot about the bridge (if it is the same one) on the bridge bash thread. It has now been raised a few inches, presumably just enough to clear most hire vans. The video of the bridge raising is well worth watching.

Jonathan

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There are quite a few bridges in the UK with sacrificial beams. When I was a plod in Pontefract there was one on the A638 near Ackworth under the Swinton and Knottingley line. This was actually in a dip in a fairly straight road so the bridge was invisible from a distance. They installed beams plus a detector system each side of the bridge that set off flashing lights and signposted a diversion, yet still the beams got bashed on a regular basis. Several of these involved container lorries and the flying containers caused several fatalities over the years when they hit vehicles coming the other way.  Not nice to deal with.  I suppose the moral is that however many warning systems you put in there will always be some idiot who ignores them all.

 

Jamie

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Posted (edited)

Is the fact that most of the trucks hitting the beam in the 11' 8" videos are rental ones telling?

 

"My usual vehicle passes under it..."

 

The raising of the bridge by 8" hasn't stopped the carnage. There have been at least three videos released of vehicles having things trimmed off the top of them since the work was completed.

Edited by talisman56

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3 hours ago, corneliuslundie said:

I assume you are referring to the sacrificial beam rather than the signal system, which seems to be ignored regularly at that bridge. BTW there is a lot about the bridge (if it is the same one) on the bridge bash thread. It has now been raised a few inches, presumably just enough to clear most hire vans. The video of the bridge raising is well worth watching.

Jonathan

 

I was indeed referring to the sacrificial beam.

 

 

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On 23/05/2020 at 18:32, Joseph_Pestell said:

I am perfectly familiar with the location. I used to drive around there every weekday.

And building a new bridge to the east creating yet another Steventon bypass would offer benefits for the locals.   And of course there is no need at all for people driving from the Hanneys or Stanford-in-the-Vale to come via Steventon - I'd no more think of going through Steventon to get to the Hanneys from the A 417 or Harwell than I would think of going through Wantage  (And yes - that's a journey I used to make regularly, it has never even occurred to me to go via Steventon in order to get from the A417 to East Hanney).

 

I think the matter of local pressure groups saying the 'right' thing, or knowing the right people to say it to, has very much been the case at Steventon in respect of this bridge rebuild just like certain folk at Goring who seem to object to just about everything proposed to happen there (but with less success)   Something which, i think, is inevitable about the former A34, now B4017, bridge over the railway at Steventon is that after years of heavy traffic it is going to one day need far more substantial repair work, and possibly strengthening, than all the previous work which has been done on it and has already altered parts of it from its original design and materials.   It obviously would be great if a bit of imagination could be used in respect of ohle tension etc to raise the linespeed under the bridge back to 125 mph but whether that happens or not one day the bridge is still likely to need some substantial work which might well require road closure.

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On 23/05/2020 at 23:10, talisman56 said:

 

Similar to this one?

 

 

 

I don't suppose that there are many really big HGVs that visit the industrial estate which lies to the south of the railway. But I think that the existing tenants there would have a legitimate grouse if the possibility of delivery by such vehicles was now prevented. In particular, when I was regularly visiting there (most days) there was a toy wholesaler doing large volumes of parcels.

 

But there is such an easy solution available by way of rebuilding Station Lane which runs along the south side of the railway. Rebuilding is perhaps the wrong word as some rerouting would be involved to make it wide enough for heavy traffic. The difficulty is that to straighten and widen Station Lane involves cutting into the allotments. As a former Town Councillor, I know all too well the uproar that will cause! But plenty of land around there to provide new allotments. 

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On 22/05/2020 at 21:21, St. Simon said:

Hi,

 

For those that are interested, despite COVID, next Sunday afternoon should see electric operation through the Severn Tunnel.

 

This will mean that the GWML electrification scheme is finished*
 

*well, not ‘finished‘, but the current scope has been complete, for now..... ;)

 

Simon

 

I gather (from another forum) that the first train operating on electric throughout the tunnel this afternoon was 1L68 1422 Swansea to Paddington formed with 800305. 

 

 

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On 30/05/2020 at 19:41, The Stationmaster said:

 

I think the matter of local pressure groups saying the 'right' thing, or knowing the right people to say it to, has very much been the case at Steventon in respect of this bridge rebuild just like certain folk at Goring who seem to object to just about everything proposed to happen there (but with less success)   Something which, i think, is inevitable about the former A34, now B4017, bridge over the railway at Steventon is that after years of heavy traffic it is going to one day need far more substantial repair work, and possibly strengthening, than all the previous work which has been done on it and has already altered parts of it from its original design and materials.   It obviously would be great if a bit of imagination could be used in respect of ohle tension etc to raise the linespeed under the bridge back to 125 mph but whether that happens or not one day the bridge is still likely to need some substantial work which might well require road closure.


As I understand it there is an aspiration to fit ECTS to the GWML away from London so that the class 800s can utilise their 140mph Capability in future. Were that to happen then the need to sort out the bridge once and for all would be essential.

 

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Posted (edited)
10 hours ago, phil-b259 said:


As I understand it there is an aspiration to fit ECTS to the GWML away from London so that the class 800s can utilise their 140mph Capability in future. Were that to happen then the need to sort out the bridge once and for all would be essential.

 

 

Having not seen that acronym before, I Googled 'ECTS' and after trawling through all the references to the 'European Credit Transfer [and Accumulation] System', I realised the above reference should be 'ETCS' ('European Train Control System')... :blush:

Edited by talisman56
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The reason for ECTS on the GWML is more likely to be to get rid of the obsolete ATP (Automatic Train Protection) system that has been in use on that line since the 1990s.  It can't just be switched off, as that would represent a reduction in safety even though the simpler TPWS system already fitted on GWML would catch about 70% of the accident risk.  Most trains on the GWML stop often enough that they wouldn't get much above 125mph anyway - the new fast Bristol and Cardiff trains would, but might just catch up with the slower train in front.  

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14 minutes ago, Edwin_m said:

The reason for ECTS on the GWML is more likely to be to get rid of the obsolete ATP (Automatic Train Protection) system that has been in use on that line since the 1990s.  It can't just be switched off, as that would represent a reduction in safety even though the simpler TPWS system already fitted on GWML would catch about 70% of the accident risk.  Most trains on the GWML stop often enough that they wouldn't get much above 125mph anyway - the new fast Bristol and Cardiff trains would, but might just catch up with the slower train in front.  


If there was no aspersions for 140mph running then the OLE could have been made cheaper - and equally there would have been no need for the class 800s to be designed for 140mph running.

 

Agreed faster running is not the sole reason for ETCS, but if you are going to the trouble of installing it and the trains are 140mph ready then why not?

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The 800s 140mph capability might be more useful in the ECML application, if that gets ETCS before HS2 takes all the fastest trains off the route (and there's enough fast running north of York that the HS2 trains and 800s could make use of 140mph running there too).

 

Though I'd expect that there's enough sections of the GWML between London and Bristol where 140 would be achievable that it would be worth designing the ETCS system to allow it.

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6 minutes ago, Zomboid said:

 

Though I'd expect that there's enough sections of the GWML between London and Bristol where 140 would be achievable that it would be worth designing the ETCS system to allow it.


Given that HST’s managed 140 often enough before limiters were used, it ought to be a doddle for the replacement. :D

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47 minutes ago, Zomboid said:

The 800s 140mph capability might be more useful in the ECML application, if that gets ETCS before HS2 takes all the fastest trains off the route (and there's enough fast running north of York that the HS2 trains and 800s could make use of 140mph running there too).

 

Though I'd expect that there's enough sections of the GWML between London and Bristol where 140 would be achievable that it would be worth designing the ETCS system to allow it.

I guess it's down to whether there's a business case to justify the increased track/OHL/rolling stock maintenance & energy costs. 140 is only likely to knock a few min off the Cardiff/Bristol-Paddington times, is that going to attract enough extra seat cargo?

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26 minutes ago, rodent279 said:

I guess it's down to whether there's a business case to justify the increased track/OHL/rolling stock maintenance & energy costs. 140 is only likely to knock a few min off the Cardiff/Bristol-Paddington times, is that going to attract enough extra seat cargo?

BR always reckoned that 1 minute of time saved increased revenue by 1% so if that still holds then I would say even 3 or 4 minutes saved is worth it.

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Trouble is, 3 or 4% increased revenue in the near future is not likely to be worth anything near as much as it was a few months ago...

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But maybe every % of extra revenue will be even more critical. Who knows...

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